Dusting apparatus



June 7, 1938. e. SCHANZ nus'rme APPARATUS Filed July 21, 1937 2711 5777271? 2 ESE/75272 I 5502? 2 flw Patented June 7, 1938 DUSTIN G APPARATUS,

George H. Schanz, Akron, Ohio, assignor to The B. F. Goodrich Company, New York, N. Y., a corporation oi New York Application July 21, 1937, Serial No. 154,823

3 Claims.

This invention relates to apparatus for applying dust to a surface such, for example, as the surface of rubber composition. v

In the manufacture of articles of plastic material such as rubber compositions or the like, it is customary to apply a coating of dust to the adhesive surfaces of the material to prevent the material from adhering to similar material with which it comes in contact. Materials such as powdered mica, soapstone, flour, or starch are ordinarily used for this purpose.

The principal objects of this invention are to provide dependable and positive operation, to provide simplicity of construction, and to provide uniformity of deposit.

These and other objects will appear from the following description and the accompanying drawing.

0f the drawing:

Fig. 1 is an elevation, partly in section, constructed according to and embodying the invention in its preferred form for applying dust to the liner surface oi an extruded rubber tube, part of the extruding machine and a conveyor being also shown.

Fig. 2 is a cross-sectional view taken on line 2-2 of Fi 1.

Fig. 3 is a cross-sectional view taken on line 33 of Fig. 1.

Fig. 4 is a detail sectional view of the air valve.

Referring to the drawing, the numeral l 0 designates a dust receptacle having a conical funnel- (like bottom Ii formed with a central outlet tube 12. A cover 13 at the top of the receptacle serves as a platform to support an electric motor M which, through a speed reducer l5 of the worm and gear type, drives a vertical shaft l6 which extends through the receptacle and is journaled in a bearing l1 fixed to the cover l3 and in the outlet lZ'at its lower end. A longitudinal groove l8 formed in the shaft I6 Where it enters the outlet I2, provides for passage of the dusting inaterial l9 past the end of the shaft. A plurality of mixer blades 20, fixed to the shaft l6, have surfaces inclined with respect to the axis of the shaft and fit closely in the funnel portion of the receptacle so as to plough up the dust l9 and mix it with the air in the receptacle, so that it will be kept well stirred and packing of it will be avoided.

The outlet tube l2 enters from the side, and preferably at an acute angle, an ejector tube 2| within which is axially mounted a jet tube 22 having 'a head 22a of enlarged diameter located in a constricted portion 23 oi the ejector tube, and

therewith defining a restricted passage 24 adapted to increase the velocity and therefore to reduce the pressure of dust-laden air flowing from the pipe I2. The jet tube 22 is screw-threaded as at 25 to fit a threaded counter-bore 26 of the ejector tube and tliereby to provide for adjustment of the jet longitudinally of the ejector pipe. The ejector tube 21 may be connected by any conduit, such as the rubber hose 21 so as to deliver the supply of air-laden dust to the work. As shown in the drawing the hose 2! may connect through the die 28 of an extruding machine whereby the dust is delivered to the inner surface of a plastic rubber tube 29 progressively as the tube is formed so as to prevent the inner surfaces from adhering to each other upon collapse of the tube.

As the dust is inclined to'settle out of the air, it is found desirable to deliver the air from the jet tube in a series of spurts whereby vibration of the air in the hose 2'! is utilized to keepthe dustcarrying stream constantly agitated. For this purpose, the air line 30, which supplies the jet 22 is supplied with a valve 3| which may be of the whistle type, including a valve body 3la having a dividing partition in which is formed a seat for a plunger 3lb, the stem of which extends from the body and may be depressed to open the valve which isnormally closed by a spring 3lc and the pressure of the air in the pipe 30. The plunger of the valve is adapted to be intermittentlydepressed by one end of a lever 32 fulcrumed as at 33 on the cover l3 and carrying a roller 34 adapted to follow a cam disc 35 fixed to shaft H5. The cam disc is formed with a series of projections 36 adapted intermittently to raise the roller 34 and thereby to release spurts of air from the jet 22.

To provide for filling the container ID a hinged portion 31 of the cover overlies a hopper 38 and is hinged at 39 to the cover l3.

Modifications may be made within the invention as it is defined in the following claims without departing from the scope thereof.

I claim:

1. Apparatus for supplying a. mixture of air and dust comprising a dust receptacle having an outlet discharging into an ejector, a positively driven dust agitator-in said receptacle, a valve for positively controlling supply of pressure fluid to the ejector, and means controlled by movement of the dust agitator for operating said valve..

2. Apparatus for supplying a mixture of air and dust comprising a dust receptacle having an outlet discharging into an ejector, a positively driven dust agitator in said receptacle, a valve for positively controlling supply of pressure fluid to the ejector, and means controlled by movement oi the dust agitator i'or intermittently opening and closing said valve.

3. Apparatus as: supplying a mixture of air 5 and dust comprising a dust receptacle having an outlet discharging into an ejector. a positively driven dust agitator in said receptacle, a wave tor positively controlling supply of pressure fluid to the ejector, and means controlled by movement of the dust agitator tor intermittently opening and closing said valve.

. GEORGE H. BCHANZ. I 

